Chemical Reactors III
Objectives
The main goals of this course are:
· To inculcate in the students the notion of the complexity of the catalytic process, namely the notion of that is not only the chemical reaction that has an important role in the determination of the rate of the global process, but that also mass transference, external or internal, can be crucial in the calculation of the necessary parameters to the reactor design and sizing or to the simulation of its behaviour.
· To supply to the students of Chemical Reaction Engineering the description of the main types of catalytic reactors and of the mathematical models allowing to simulate its operation and to determine the main operational parameters.
With the aquired knowledge the students should be able to:
· To consider reactional mechanisms for a catalyzed reaction, to derivate the corresponding kinetic models, to determine the parameters of these models and to choose the model that is better fitted to the experimental kinetic data.
· To determine if a given catalytic process is limited by the chemical reaction or mass transfer, external or internal.
·To simulate the operation of a catalytic reactor, by using the appropriate mathematical models, and to determine the parameters that allow the reactor sizing, namely conversion, weight of catalyst or reactor volume.
General characterization
Code
11053
Credits
6.0
Responsible teacher
Teresa Maria Alves Casimiro Ribeiro
Hours
Weekly - 4
Total - 64
Teaching language
Português
Prerequisites
There are no requirements.
Bibliography
1. | H. Scott Fogler, Elements of Chemical Reaction Engineering, 4rd edition, Prentice-Hall, 2006. |
2. | J.L. Figueiredo e F. Ramôa Ribeiro, Catálise Heterogénea, Fund. Calouste Gulbenkian, 1989. |
3. | Francisco Lemos, José Madeira Lopes, Fernando Ramôa Ribeiro, "Reactores Químicos", IST Press, Lisboa 2002 |
4. | G. Froment, K. Bischoff, Chemical Reactor Analysis and Design, 2nd edition, John Wiley & Sons, 1990 |
Teaching method
The course is available in a web page (Moodle@FCT).
This course is composed by a theoretical part consisting in PowerPoint presentations, and a practical part. Lessons are available via web page.
The practical part consists in one laboratory session where the demonstration of the fluidization of a catalytic bed is performed, and in teorethical-practical sessions in which the practical works are perfomed by using Microsoft Excel and MatLab as tools.
Some theoretical-practical sessions are reserved to problems resolution.
Evaluation method
The course evaluation is composed by a written part and a practical part. The written part consists in two tests and/or in a final exam. The practical part consists in projects based in the laboratory sessions and in the theoretical-practical sessions. Each project is executed by groups of three or four students, is electronically delivered to the instructors and leads to a single grade.The course final grade is the weighted average of the written and practical parts, with weights of 40% and 60%, respectively. Aproval will be obtained with a minimum grade of 10/20. The minimum grade of the writen part must be 9/20 and the minimum grade of the practical part must be 10/20.
Subject matter
Transport and reaction in solid catalyts.
Internal gradient effects: modelling of diffusion in porous systems; diffusion and reaction in porous catalysts – the generalized modulus; non isothermal catalyst pellets.
Heterogeneous catalytic reactors:
The fixed bed reactor: unidimensional pseudo-homogeneous models; the fixed-bed reactor with axial diffusion; The closed-closed vessel model of Danckwerts - boundary conditions; non isothermal operation.
The fluidized bed reactor: aspects of fluidization and solid transport; The Kunii-Levenspiel model.
Multiphase reactors: the trickle-bed reactor and the slurry reactor.
Membrane reactors: classification of membrane reactors; inert membranes and catalytic membranes; exemples of membrane reactors; modelling of catalytic membrane reactors: dense and porous membranes; multiple reactions in membrane reactor.